1. Field of the Invention
The present invention relates generally to an apparatus and method for configuring telephony, and more particularly, to an apparatus and method for configuring High-Definition (HD) video telephony between computer devices.
2. Description of the Related Art
The development of mobile networks and portable terminals has led to the decrease of cellular phone communication fees, resulting in the rapid growth of the cell phone market.
Additional services other than voice communication have also been developed, which has led to the current era of video communication.
Use for such a mobile service has expanded in scope to in-home, and techniques such as Universal Plug and Play Telephony (UPnP) allowing use of cell phone functions by using a Computer Engineering (CE) device such as a TeleVision (TV) in premises, have emerged.
The UPnP telephony is a technique for interworking the CE device with a telephony device, with which technique a user can send or receive a call by using the TV in the house, regardless of a type of the telephony device.
The UPnP telephony is advantageous in that it can be used by interworking with not only a mobile telephony service, but also an existing telephony technique such as Voice over Internet Protocol (VoIP) and Public Switched Telephone Network (PSTN). In addition, since the UPnP telephony also has the same UPnP device architecture as the Digital Living Network Alliance (DLNA), which is a standard for media sharing in the premises, it is likely to be adopted as a next-generation standard of the DLNA.
Techniques for covering similar areas to the UPnP telephony include Session Initiation Protocol (SIP)-based Gm* which is under standardization in Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN) and Cordless Advanced Technology—internet and quality (CAT-iq) for premises cordless phone connection.
FIG. 1 illustrates a conventional UPnP telephony system, which includes a telephony service provider 101, an UPnP telephony control point (or a control point) 102, a telephony server (or terminal) 103, and telephony client (or electronic device) 104.
Herein, the telephony terminal 103 and the electronic device 104 are located in a space in which they can communicate with the control point 102 by using the UPnP protocol.
The telephony service provider 101 provides both a telephony service and an interface for transmitting and receiving calls to the telephony terminal 103.
The control point 102 is a logical software module for controlling a UPnP telephony server 106 and a UPnP telephony client 109 by using a UPnP action. Although the control point 102 may be provided in a device such as a Personal Computer (PC) or a Personal Digital Assistant (PDA), separately from the telephony terminal 103 and the electronic device 104, it may also be provided in a physical device such as the terminal telephony 103 or the electronic device 104, in which case the control point 102 may directly control the UPnP telephony server 106 or the UPnP telephony client 109 without using a UPnP action.
The control point 102 determines a media, protocol, and transmission format to be used for call transmission and reception by using capability information of a call data transmission agent, which is transmitted from the UPnP telephony server 106 and is included in the UPnP telephony server 106 or the UPnP telephony client 109. The control point 102 generates a profile in which the determined media, protocol, and transmission format are defined, and transmits the profile to the UPnP telephony server 106 or the UPnP telephony client 109, thereby setting the environment of the call data transmission agent included in the telephony terminal 103 or the electronic device 104.
The telephony terminal 103 is a physical device, such as a CE device, a telephone, a PC including VoIP configured with software, or a mobile communication terminal interworking over a communication network. The telephony terminal 103 includes the UPnP telephony server 106 configured with software, and controls call transmission and reception by using the telephony service provider 101 for providing a telephony service and an interface provided by the telephony service provider 101.
The electronic device 104 is a physical device, such as a CE device, a PC or a TV capable of inputting and outputting voice or an image of a user, or a mobile communication terminal or a video phone, and includes the UPnP telephony client 109 configured with software. As such, a user can conveniently transmit and receive a call in home by using a home network system.
FIG. 2 illustrates a situation in which users perform video communications by using UPnP telephony in their respective homes.
In FIG. 2, Bob and Alice perform cell phone video communications by using CE devices, such as TVs, as video and voice input/output devices in their homes. The TV includes a video input device such as a camcorder, and an image input through the camcorder is transmitted to a third-generation (3G)/Long Term Evolution (LTE) network through a cell phone. A cell phone 201 of Alice, which has received the image, transmits the received image to a TV 200 to display the image of Bob. In the same manner, an image of Alice is transmitted to a TV 203 of Bob.
When a conventional technology based on UPnP telephony is used, image traffics transmitted over the 3G/LTE network has limited quality based on an allowed bandwidth between mobile phones.
The image traffic is specialized for use in cell phones and thus has low image resolution, and the bandwidth of the 3G/LTE network is not large, thus rendering likely a phenomenon such as image disconnection.
Since a TV has a larger display size than a cell phone, image enlargement is required to see a low-definition image on the TV. When the low-definition image is enlarged, the image may be distorted or blurred.
Conventionally, only a video stream is supported to the extent supported by a telephony server, regardless of the maximum performance of a telephony client to be used by the user.
In case of communication between a TV and a cell phone, a user of the cell phone can see a video call screen, but a user of the TV inconveniently sees an enlarged low-definition image.
Such a problem is aggravated when both users use TVs. Even if the problem were solved, transmission of an HD image would be impossible without an improvement to the 3G/LTE network that transmits a video stream of the video communication.
Moreover, the foregoing image distortion may be experienced when both users perform communication by using TVs having embedded UPnP telephony technologies.
When a field of a Session Initiation Protocol (SIP) is extended to find out information of a home network to which a peer cell phone belongs and to partially set a function of a peer TV, phones of both users, which have embedded SIP User Agents (UAs) therein, may transmit information by using an additional field of the SIP. However, when only a conventional mobile network is supported, the information cannot be transmitted. Further, if a field is newly defined in an SIP body, a conventional SIP server would filter and remove the field.